The Effect of Using Visicoil Fiducial Marker

A Alkhatib1*, (1) ,

Purpose: In our clinic we are looking to start using Visicoil fiducial marker for prostate. This study is to see the effect of using Visicoi Fiducial marker.

Methods and materials: Tissue equivalent solid phantom and 1 gold marker (1.10 mm diameter * 10mm).. The gold marker was placed at 4 cm depth and three LiF (TLD-100) size 3.2mm2 * 0.9mm)was placed at 2 mm downstream position relative to the gold marker. We used a16 MVphoton beam and 10 *10 cm2 field size. The phantom was set at 100 cm SSD. 200MUwas delivered. After the gold was removed, another f three TLD were irradiated withthe same photon beam, field size, and SSD. TLD Were analyzed with Harshaw TLD reader 3500. Microsoft Office Excel was also used to analyze the dataResults and discussion: We found that adding the fiducial marker caused a 15% dose enhancement. Because the pair production dominates at this energy andwith high Z material (gold foil), it is possible that the enhancement was due to the pairProduction.Conclusions: This study showed that there is dose enhancement between due to gold MarkerThe result suggests the possibility of hot spots up to 15 % due to this type of fiducial marker .